602 SUMMARY OF CURRENT RESEARCHES RELATING TO 



The author designates this bacillus Bacterium pyogenes ramosum,. 

 and considers it as belonging to the Proteus group. 



Bacillus Pathogenic to Rats.* — Issatschenko records some further 

 experiments with a bacillus pathogenic to the grey rat, previously de- 

 scribed by him.j This organism was fatal in 431 out of a total of 

 443 rats experimented upon, — when injected in pure culture death 

 usually taking place from the seventh to the tenth day after infection. 

 Domestic animals appear to be totally insusceptible to the bacillus. 

 The author fed 2 cats, 1 dog, 2 hens, and 4 pigeons with highly virulent 

 cultivations of the bacillus in doses varying from 20 ccm. to 200 ccm. 

 No ill effects followed, whilst control rats provided with infected food 

 died 7, 8, 10, and 11 days after feeding. The author also quotes 

 Feoktistoff's experiments, in which the horse, ox, pig, sheep, dog, cat, 

 turkey, hen, goose, and duck were fed with varying doses, ranging from 

 500 ccm. in the case of the horse down to 20 ccm. for the duck, without a 

 fatal result being produced in any of the experimental animals. The 

 author also states that large quantities of broth cultivations have been 

 sent out from his laboratory to be employed for the purpose of destroying 

 rats on farms, and in granaries and dwelling-houses, and the reports of 

 its action testify to its value. 



Heat-resisting Micrococcus.^ — Russell and Hastings describe a 

 micrococcus which is capable of retaining its vitality in milk heated to 

 60° C, and which they isolated in large numbers from samples of 

 pasteurised milk. The organism occurs usually in pairs or bunches of 

 four, individual elements having their adjacent sides flattened, and 

 showing a clear bright line between. The coccus stains easily with 

 anilin dyes, and is not decolorised when treated by Gram's method. 

 Its optimum temperature is from 20° C. to 25° C, growth at 38° C. 

 being but very scanty. It grows well on all ordinary media ; on agar 

 it produces a dull lemon-yellow coloured layer, confined to the needle- 

 track. In broth growth begins at the bottom of the tube, ai^d creeps up 

 the side, old cultures showing a thin pellicle. In milk no change is 

 observed, the bright yellow growth being deposited at the bottom of the 

 tube. Gelatin is not liquefied. The organism does not ferment dex- 

 trose, lactose, or saccharose. In thermal death-point determinations, 

 48-hour cultures in standard nutrient broth were exposed at various 

 temperatures in thin-walled tubes of 6 mm. diameter, the results showing 

 tbat although many individuals are killed at 72° C, exposure to 76° C. 

 for fully 10 minutes is necessary to ensure the death of all. 



Association of Amylomyces and a Micrococcus. § — Vuillemin in 

 cultivating Mucor Bouxianus upon potato in association with an un- 

 named micrococcus, found that the coccus developed at the expense of 

 the sugar produced from the potato starch by the fungus. Further, 

 that, the large amount of yellowish-orange pigment elaborated by the 

 Mucor is due to the consumption of maltose by the micrococcus. 



* Centralbl. Bakt., l t8 Abt., xxxi. (1902) pp. 26-8. 

 t Cf. this Journal, 1898, p. 467. 

 t Centralbl. Bakt., 2 t0 Abt., viii. (1902) pp. 339-42. 



§ Compies Rendus, exxxiv. (1902) pp. 366-8. Si e Jonrn. Chem. Soc, Abstr. ii. 

 lxxxii. (1902) p. 343. 



